Switching apparatus

ABSTRACT

A switching apparatus comprised of a U-shaped magnetic base, the opposed yokes of which are made of a material with a large saturation magnetic flux density, a rotary yoke which is made of the same material as the yokes of the base and is mounted on to a free end of one yoke of the base, a galvano-magnetro effect device which is fixed on one internal surface of the yoke, and a magnetic piece with a smaller saturation magnetic flux which is provided at the magnetic base so that the magnetic piece closely approaches or contacts the device and is magnetically isolated from the magnetic base, wherein the moving end of the rotary yoke is magnetically connected to and disconnected from the magnetic piece along with rotation of the rotary yoke.

United States Patent Kobayashi [54] SWITCHING APPARATUS [72] Inventor: Tunekazu Kobayashi, Kawasaki, Japan [73] Assignee: Denki Onkyo Co., Ltd.

[22] Filed: Jan. 18, 1971 [21] Appl. No.: 107,367

[30] Foreign Application Priority Data Jan. 19, 1970 Japan .;....45/s634 [52] US. Cl. ..338/32, 323/94 H [51] Int. Cl ..li01c 7/16 [58] Field of Search ..338/32; 335/1, 207; 324/45, 324/46; 323/94 H; 317/235 H; 307/309 {56] References Cited UNITED STATES PATENTS 3,537,046 10/1970 Hubrich et a1 ..335/1 15] 3,657,687 Apr. 18, 1972 Primary Examiner-C. L. Albritton Attorney-James L. Armstrong and Ronald S. Cornell [57] ABSTRACT A switching apparatus comprised of a U-shaped magnetic base, the opposed yokes of which are made of a material with a large saturation magnetic flux density, a rotary yoke which is made of the same material as the yokes of the base and is mounted on to a free end of one yoke of the base, a galvanomagnetro effect device which is fixed on one internal surface of the yoke, and a magnetic piece with a smaller saturation magnetic flux which isprovided at the magnetic base so that the magnetic piece closely approaches or contacts the device and is magneticallyisolated from the magnetic base, wherein the moving end of the rotary yoke is magnetically connected to and disconnected from the magnetic piece along with rotation of the rotary yoke.

9 Claims, 6 Drawing Figures BACKGROUND OF THE INVENTION The present invention relates to'a switching apparatus comprised of a rotary yoke which is attached to the free end of one yoke of the U-shaped magnetic base and a galvano-magnetro effect device which is provided at the internal surface of the other yoke, and devised so that the free end of the rotary yoke approaches to and departs from the galvano-magnetro effect device.

The conventional switch of this type is disadvantageous because the magnetic flux applied to the galvano-magnetro effect device inevitably varies even though the gap between the rotary yoke and the device is slightly different, since a pair of yokes of the magnetic base and the rotary yoke are made of a material with the same saturation magnetic flux density and the galvano-magnetro effect device is directly fixed to one yoke of the magnetic base and it is extremely difficult to produce apparatus with the same output characteristic.

The present invention is intended to provide a switching apparatus in a simple and inexpensive construction capable of eliminating the demerit mentioned above.

SUMMARY The present invention provides a switching apparatus comprised of a U-shaped magnetic base, of which a pair of opposed yokes are made of a material with a large saturation magnetic flux density, a rotary yoke made of a material with a large saturation magnetic flux density which is rotatably mounted on the free end of one yoke of the magnetic base and has'a moving end extended toward the other yoke of the magnetic base, at least one small magnetic piece with a small saturation magnetic density which is provided near a yoke of the magnetic baseopposite the rotary yoke and is magnetically isolated from the magnetic base so that the moving end of the rotary yoke closely approachesor comes in contact with the magnetic piece and the magnetic flux flowing in the rotary yoke is concentrated onto the magnetic piece when the moving end of the rotary yoke comes to a given position, at least one galvano-magnetro effect device such as, for example, a Hall effect device or magnetro-resistance effect device which is arranged between the yoke of the magnetic base opposite the moving end of the rotary yoke and the magnetic piece, and an input power supply and external circuits such as loads, etc. which are connected to the galvano-magnetro effect device, wherein the magnetic flux density to be applied to the galvano-magnetro effect device is maintained at a fixed level by making the magnetic flux density flowing in the magnetic path consisting of the magnetic base and the rotary yoke larger than the saturation magnetic flux density of the magnetic piece.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is illustrated in detail in the accompanying drawing whereof:

FIG. 1 is a front view of the apparatus according to the present invention;

FIG. 2 is a partial magnified view of a principal portion of the apparatus shown in FIG. 1;

FIGS. 3 and 4 are partial magnified views of other embodiments of the portion shown in FIG. 2;

FIGS. 5 and 6 are front views of other embodiments of the apparatus according to the present invention.

DETAILED DESCRIPTION Referring to FIGS. 1 and 2, there is shown a switching ap paratus comprised of a U-shaped magnetic base 10, of which a pair of yokes 12 and 12, made of a material with a large saturation magnetic flux density such as, for example, mild iron, are fixed to both poles N and S of magnet 11, rotary yoke, 20 made of a material with a large saturation magnetic flux density, which is mounted on the free end, as the fulcrum, of one yoke 12 of the base and has moving end 21 extended toward other yoke 12', magnetic piece 30, made of a material such as,

for example, ferrite with a smaller saturation magnetic flux density than the pair of yokes 12 and 12', piece 30 being fixed so as to receive moving end 21 when moving end 21 of the K0. tary yoke goes down and is positioned near yoke 12', insulating and holding means 40 such as, for example, an insulating layer interposed between magnetic piece 30 and magnetic base 10 so as to magnetically insulate the former from the latter, galvano-magnetro effect device 50 (hereinafter referred to as the device) such as, for example, a Hall effect device, magnetro-resistance effect device, etc. which is fixed on the internal surface of said yoke 12' so that it is interposed between magnetic piece 30 and yoke 12'', and external circuit 60 having external load 61 such as, for example, a switching circuit containing transistors, vacuum tubes, etc. and input power supply 62, etc. which are electrically connected to device 50.

The apparatus according to the present invention is as described above.

When moving end 21 or rotary yoke 20 lowers by itself as shown with a solid line in FIG. 1, the magnetic flux flowing in the magnetic path is concentrated onto device 50 through magnetic piece 30. When rotary yoke 20 rises as shown with a broken line in FIG. 1, the gap between moving end 21 of rotary yoke 20 and magnetic piece 30 becomes large and the magnetic flux flowing in rotary yoke 20 directly flows into yoke 12; therefore the magnetic flux to be appliedto device 50 reduces vastly.

Accordingly, since the magnetic flux density to be applied to device 50 varies with vertical movement of rotary yoke 20, the output voltage or current in device 50 is forced to vary and load 61 is switched.

In this apparatus, the magnetic flux is applied by yokes 12 and 12 and rotary yoke 20 which accept a large saturation magnetic flux density to magnetic piece 30 which accepts a smaller saturation magnetic flux density than the density accepted by the yokes; thus the magnetic flux is concentrated onto device 50 through magnetic piece 30. When rotary yoke 20 comes in contact with magnetic piece 30, the magnetic flux flowing in magnetic piece 30 is larger then the saturation magnetic flux density of magnetic piece 30.

In this case, therefore, the density of the magnetic flux which flows in device 50 through magnetic piece 30 is always maintained at a fixed level in accordance with the value of the saturation magnetic flux density of magnetic piece 30.

The apparatus is as described above. Since the magnetic flux density to be applied to device 50 may be fixed if the interval between device 50 and magnetic piece 30 is constant even through the gap between moving end 21 of rotary yoke 20 and device 50 is varied among products, thus the length of magnet 11 and rotary yoke 20 which form the magnetic path need not be uniform. The apparatus is advantageous because the precision machining processes for the parts which have required many troublesome process steps may be omitted for the above reasons.

In addition, the output characteristic of the apparatus may be uniform by changing the position of magnetic piece 30 in accordance with the apparatus even when, for example, the output characteristics of many devices 50 are different, since the ptpsition of magnetic piece 30 provided may be easily aduste Since magnetic piece 30 may be positioned extremely close to device 50 or attached to it, the magnetic flux from magnetic piece 30 may be effectively concentrated onto device 50 by gaducing reluctance between magnetic piece 30 and device The apparatus according to the present invention is as described above. As another embodiment, the apparatus may be constructed as mentioned below. Yoke 12' and magnetic piece 30 may be attached to corresponding surfaces of device 50 as shown in FIG. 1 or may be separated with a gap as shown in FIG. 3. Moving end 21 of rotary yoke 20 may be directly attached to magnetic piece 30 as shown in FIG. 2, or rotary yoke 20 may be arranged to come in contact with receiving surface 31 made of mild iron with high mechanical strength which is formed on magnetic piece 30 as shown in FIG. 3 or to closely approach said surface 31 as shown in FIG. 4.

If the apparatus is formed as shown in FIG. 4, the gap may be controlled by providing stopper 13 on magnetic base 10. Thus, magnetic piece 30, if made of ferrite, may be protected from damage due to contact with the moving end of the rotary yoke. It is desirable to make magnetic piece 30 with a material the magnetic permeability of which is larger than that of yoke 12' to which the device is to be attached, for example, with ferrite if yoke 12' is made of mild iron. Thus, the concentration effect of the magnetic flux may be improved.

Magnetic piece 30 and device 50 may be provided at high positions as shown in FIG. 5 so that moving end 21 of rotary yoke 20 comes in contact with magnetic piece 30 when the rotary yoke goes up. In this case, a frame 40 made of non-magnetic material is fixed on magnetic base as insulating and holding means.

If frame 40 is thus used, a pair of magnetic piece 30 and 30' may be arranged at upper and lower portions of frame 40; therefore, the magnetic flux is concentrated alternatively onto magnetic pieces 30 and 30 when rotary yoke 20 goes up and down, thus alternately actuating two devices 50 and 50'.

Device 50 to be interposed between one magnetic piece 30 and yoke 12 may be plural or may be fixed on magnetic piece 30 as shown in FIG. 4. In this case, it is desirable to form surface 32 made of a material such as, for example, mild iron to which device 50 can be easily attached, on a surface opposite yoke 12 of magnetic piece 30. It is desirable to widen the area of magnetic piece 30 opposite device 50. For this, magnetic piece 30 opposite device 50 may be extended in the L-type form as shown in FIG. 3.

What is claimed is:

l. A switching apparatus comprised of a. a U-shaped magnetic base having a pair of oppositely positioned yokes which are made of a material with a large saturation magnetic flux density;

b. a rotary yoke made of a material with a large saturation magnetic flux density which is rotatably mounted on the free end, as the fulcrum, of one yoke of the base and has a moving end extended toward the other yoke;

c. at least one magnetic piece, made of a material with a smaller saturation magnetic flux density than that of the rotary yoke and yokes of the magnetic base, the magnetic piece being mounted on the magnetic base so that said magnetic piece is magnetically coupled to the moving end of the rotary yoke when the rotary yoke moves to a given position and a gap is formed between themagnetic piece and a yoke of the magnetic base opposite the moving end of the rotary yoke;

d. an insulating and holding means which is provided to magnetically insulate the magnetic piece and the magnetic base;

e. at least one galvano-magnetro effect device which is arranged so that the magnetic'flux is concentrated by the magnetic piece to the gap formed between the yoke of the magnetic base opposite the rotary yoke and the magnetic piece; and

f. external circuits which are connected to the galvanomagentro effect device.

2. A switching apparatus according to claim 1, wherein the device is mounted on the yoke of the magnetic base opposite the rotary yoke and the magnetic piece is attached to the device.

3. A switching apparatus according to claim 1, wherein the moving end of the rotary yoke comes in contact with the magnetic piece when the moving end comes to a given position.

4. A switching apparatus according to claim 1, wherein the moving end of the rotary yoke closely approaches the magnetic piece with a given gap when the moving end comes to a giveniposition,

5. switching apparatus according to cla1m 1, wherein the magnetic piece is made of a material with a greater permeability than that of the yokes of the magnetic base.

6. A switching apparatus according to claim 1, wherein the magnetic piece opposite the device is extended in L-type form and its opposed surface is enlarged.

7. A switching apparatus according to claim 1, wherein a non-magnetic frame is employed as an insulating and holding means, magnetic pieces are mounted respectively on upper and lower portions of the frame, and at least one device is arranged in each gap between a pair of said magnetic pieces and the yoke of the magnetic base opposite the magnetic pieces.

8. A switching apparatus according to claim 1, wherein the device is fixed on the surface of the magnetic piece opposite the yoke of the magnetic base.

9. A switching apparatus according to claim 1, wherein the rotary yoke is made of the same material as the opposed yoke of the magnetic base. 

1. A switching apparatus comprised of a. a U-shaped magnetic base having a pair of oppositely positioned yokes which are made of a material with a large saturation magnetic flux density; b. a rotary yoke made of a material with a large saturation magnetic flux density which is rotatably mounted on the free end, as the fulcrum, of one yoke of the base and has a moving end extended toward the other yoke; c. at least one magnetic piece, made of a material with a smaller saturation magnetic flux density than that of the rotary yoke and yokes of the magnetic base, the magnetic piece being mounted on the magnetic base so that said magnetic piece is magnetically coupled to the moving end of the rotary yoke when the rotary yoke moves to a given position and a gap is formed between the magnetic piece and a yoke of the magnetic base opposite the moving end of the rotary yoke; d. an insulating and holding means which is provided to magnetically insulate the magnetic piece and the magnetic base; e. at least one galvAno-magnetro effect device which is arranged so that the magnetic flux is concentrated by the magnetic piece to the gap formed between the yoke of the magnetic base opposite the rotary yoke and the magnetic piece; and f. external circuits which are connected to the galvano-magentro effect device.
 2. A switching apparatus according to claim 1, wherein the device is mounted on the yoke of the magnetic base opposite the rotary yoke and the magnetic piece is attached to the device.
 3. A switching apparatus according to claim 1, wherein the moving end of the rotary yoke comes in contact with the magnetic piece when the moving end comes to a given position.
 4. A switching apparatus according to claim 1, wherein the moving end of the rotary yoke closely approaches the magnetic piece with a given gap when the moving end comes to a given position.
 5. A switching apparatus according to claim 1, wherein the magnetic piece is made of a material with a greater permeability than that of the yokes of the magnetic base.
 6. A switching apparatus according to claim 1, wherein the magnetic piece opposite the device is extended in L-type form and its opposed surface is enlarged.
 7. A switching apparatus according to claim 1, wherein a non-magnetic frame is employed as an insulating and holding means, magnetic pieces are mounted respectively on upper and lower portions of the frame, and at least one device is arranged in each gap between a pair of said magnetic pieces and the yoke of the magnetic base opposite the magnetic pieces.
 8. A switching apparatus according to claim 1, wherein the device is fixed on the surface of the magnetic piece opposite the yoke of the magnetic base.
 9. A switching apparatus according to claim 1, wherein the rotary yoke is made of the same material as the opposed yoke of the magnetic base. 